Water Intake Calculator
Estimate a daily water volume from body weight, activity level, climate, and a base mL per kilogram rate (default 33). Results appear in liters, milliliters, and US fluid ounces. Informational, not medical advice for illness or kidney disease.
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How to estimate water intake
- Choose kilograms or pounds for body weight.
- Enter weight, then pick activity from sedentary through extra active.
- Select normal, hot, or cool climate.
- Keep 33 mL/kg or type another base rate between 20 and 60.
- Read liters, milliliters, and fluid ounces. Nothing is uploaded.
Daily water estimate
mL/kg × activity × climate
| Base rate | Default 33 mL per kg (20 to 60 allowed) |
|---|---|
| Activity factors | 1.0 to 1.3 from sedentary to extra |
| Climate factors | Hot 1.15, cool 0.95, normal 1.0 |
| Outputs | Liters, mL, US fl oz and cups |
| Related entities | TDEE, BMI, dog water |
| Advice | Informational. Not illness hydration advice. |
What this water intake estimate is
The page builds a rule-of-thumb fluid target from body mass, then scales it for how active you are and how hot or cool the climate setting is. It does not replace thirst, urine color checks, or clinician guidance for disease states.
How the volume is computed
mL = kg × (mL per kg) × activity factor × climate factor. Activity factors run from 1.0 (sedentary) to 1.3 (extra). Hot climate multiplies by 1.15; cool by 0.95. Liters are milliliters divided by 1000.
Fluid, energy, and related pages
Entities include base mL/kg, activity factor, climate factor, and daily volume. Energy context lives on TDEE. Size context is BMI. Canine fluid sketches sit on dog water intake.
Use cases
Setting a starting bottle goal for a desk day versus a hot outdoor day. Teaching how mL/kg scales with mass. Comparing human and dog pages in a classroom. Not a protocol for heat stroke, pregnancy, or kidney disease.
Default numbers
At 70 kg, 33 mL/kg, moderate activity (1.1×), normal climate: mL = 70 × 33 × 1.1 × 1 = 2541 mL, about 2.54 L.
Limits
Coffee, alcohol, high-sodium meals, and medical conditions are not modeled. Overhydration can be harmful; this page does not clear large intakes as safe. Informational only. See the disclaimer. CZNull does not receive the numbers.